Plate type heat exchanger



April 2, 1957 A. B. LJUNGSTRM PLATE TYPE HEAT EXCHANGER Filed March 1l, 1953 Fig. 1

United States Patetf-O PLATE TYPE HEAT EXCHANGER ke Birger Ljungstrm, Stockholm, Sweden, assigner to Aktiebolaget Rosenblads Patenter, Stockholm, Sweden, 1-

This invention relates to plate heat exchangers comprising a plurality of longitudinally extended heat transferring plates of thin sheet metal or plate material which are clamped together side surface by side surface in spaced relation so as to form a pack of plates and with border packings or gaskets interposed between adjacent plates of the pack to surround the major portion of the side surfaces and the spaces therebetween, so as to form closed passage-ways between the plates for the heat exchanging media. In the area of the plate surrounded by said packings or gaskets the plates are provided with ridges formed by deformation of the plate material and extending in various directions over the surface of the plate.

The plates are substantially identical at least as regards the position and shape of said ridges and it is one object of the invention to provide plates of this kind adapted to be assembled to the aforesaid packs in such a way that said ridges of adjacent plates will abut against one another within the area surrounded by the border packing, preferably at a large number of places.

According to the invention this result is achieved by arranging the ridges in such a way that on assembling a pair of plates of this kind in said spaced relation with their coresponding side surfaces equally directed and with one plate of the pair rotated relative to the other plate of the same pair through an angle of 180 around an axis perpendicular to the side surface of the plate, said ridges of one plate of the pair will cross ridges of the other plate of the same pair in the space between the plates, at least some of said ridges extending beyond the side surface of the associated plate to such a level that they will abut against crossing ridges of the other plate at a predetermined minimum distance between the plates.

The invention also relates to a heat exchanger composed of a plurality of plates of the type now described.

The invention will be described more in detail with reference to the annexed drawing which diagrammatically and by way of example illustrates an embodiment of the invention.

Figure 1 is a side view of two heat exchanger plates according to the invention assembled together as a pair of adjacent plates in a heat exchanger.

Figure 2 is a top view of the plates in Figure 1, without border packings.

Figure 3 is a sectional view of the same plates taken on the line III-III in Figure 1.

Each plate 1a and 1b respectively is provided with a border packing 2a and 2b respectively, and in the zone within said packings the plates have ridges 4a, Sa and 4b, 5b respectively pressed out from the material of the respective plate in opposite directions. Between each pair of ridges or ribs such as 4a and 5a there is a web of plate material whose extent from the peak of one ridge to the peak of the other is somewhat greater than twice the height of one of said peaks measured from the center plane of the plate.

The ridges are arranged in pairs so as to form groups 6a, 7a and 8a respectively on pla-te 1a and groups 6b, 7b and 8b respectively on plate 1b. The ridges extend obliquely to the longitudinal direction of the plate. The pattern of ridges is identical on both plates of the pair but'one plate is rotated in relation to the other plate through an angle of around an axis perpendicularly to its side surface, whereby the ridges are caused to cross and to bear against each other in the space between the plates.

As shown in the drawing the ridges are so arranged that at least one ridge portion on one surface of the plate and a ridge portion on the opposite surface thereof at some point extend in mutually crossing directions in the plane of the plate at equal distance from but on diametrically opposite sides of the aforesaid axis of rotation.

Each plate of the pair yis provided with openings, namely 10a, 11a, 12a and 13a in one plate and 10b, 11b, 12b and 13b in the other plate. On account of the position of the plates in relation to each other the openings 10a and 12b, 11a and 13b, 12a and 10b, 13a and 11b respectively, are situated in registering positions. The openings serve to pass the heat exchanging media to and from the separate spaces between the plates of the heat exchanger in a manner known to anybody skilled in the art. In the arrangement of the border packing shown in the drawing the heat exchanging media are caused to pass through said spaces between openings situated at one and the same edge of the plate, but it is obviously also possible within the scope of the invention to arrange the border packing so as to enable passing of said media between diagonally opposite openings.

It is clear that a person skilled in the art will be able to produce a multiple of further modifications within the scope of the invention. The ridges could for instance be arranged in many other patterns such as transverse or longitudinal zigzag lines, transverse or longitudinal rows of relatively short oblique ridges etc., or in the form of a large number of groups of a large number of ridges, in the form of a continuous one-sided or double-sided corrugation or in the form of combinations of such modifications. The last modification will result in the largest number of abutting places between the ridges.

What I claim is:

A plate exchanger for heat exchanging media comprising in combination, a plurality of separable identically shaped elongated substantially rectangular plates of light gauge sheet metal stock material arranged in stacked relationship to form immediate adjacent paths for the tiow of the different media, each of said plates having a communicating opening for heat exchanging medium through each corner portion of the plate, said openings being arranged in rectangular relation to each other, and corrugations formed integral with each plate in the heat exchange area thereof, said corrugations providing ribs on each side of said plate and extending across the plate in chevron pattern symmetrically with respect to the longitudinal center line of the plate, adjacent oppositely extending pairs of said ribs being separated by a web of plate material, the extent of said web from the peak of the rib on one side of the center plane of the plate to the peak of the next adjacent rib on the other side of the center plane of the plate being substantially twice the height of one of said peaks from said center plane, each of said plates having their corresponding side surfaces facing in the same direction and each of said communicating openings being in alignment with one of said openings of an adjacent plate, every second plate being positioned in its plane at 180 about an axis normal to its center with respect to the plate opposed to it so that the identical chevron patterns of adjacent plates are reversed in relation to each other, with the peaks of the respective ribs of each pair of opposed plates crossing and abutting in a icc plurality of crossing contact points to maintain internal rigidity` and constant spacial relation between any pair of plates and for all plates in the assembly, the valleys formed by the respective ribs serving as passages for the flow of the medium and the crossing pattern of' the valleys of said opposed plates introducing deections in the interplate low path whereby turbulent flow and increased heat transfer between the film of the medium and the plate is achieved'.

References Cited in the le of this patent UNITED STATES PATENTS Newman June 20, 1933 Feldmeier Apr. 28, 1936 Neveu Aug. 17, 1937 Groat Nov. 28, 1939 Getz Apr. 22, 1952 Hytte Sept. 16, 1952 Ludlow Aug. 4, 1953` 

